I discovered my home’s extension potential in seconds – here's how you can too

A stone cottage with glass box extension to extend the ground floor as well as link the cottage areas more effectively
We've created a quick and easy way to check your home's extension potential (Image credit: Mark Ashbee)

If you're in the early stages of planning an extension, you'll need as much information as possible to ensure the process runs smoothly and efficiently – from the planning risks that could get in the way to the costs you might expect to pay.

That’s why we’ve teamed up with architectural services company Resi to create Extension Potential – an online tool that produces a bespoke analysis of your home, presenting all the key info you need to know. These results usually take weeks to secure, but you can now get them in a matter of seconds for free.

To learn more about this fantastic new tool and how you can get a quick, free report on your home, keep reading.

What is Resi Extension Potential?

The Resi Extension Potential tool is an excellent first step for homeowners interested in extending their homes. Instead of waiting to weeks to find out whether an extension is possible (and the planning risks and costs that could be involved) it will give you an answer instantly.

Nic Yeeles, CEO of Resi Labs, says, "The stress of extending begins right at the start when you're simply trying to work out whether it's even possible. Can I extend my property? What might prevent planning permission? How much would an extension cost? Answering those questions today means weeks of research or expensive conversations with professionals before you've even made a decision.

"That's why we built Extension Potential – a new tool in partnership between Homebuilding & Renovating and Resi that helps homeowners answer those questions in seconds rather than weeks."

Extension on house

Forget waiting weeks for answers find out in seconds if your home could be eligible for an extension (Image credit: David Valinsky Photography)
Nic Yeeles
Nic Yeeles

Nic Yeeles is the CEO of Resi Labs, which is part of Resi Group, the UK’s leading architectural service.

How do I use Extension Potential?

To find out whether your home can be extended, use the Extension Potential tool below:

How does the Extension Potential tool work?

No matter what your tech capabilities are, the Extension Potential tool is designed to be quick and straightforward to use, with results loading within seconds.

All you need to do is enter your postcode, select your address, and answer a few simple questions about your property. Our tool will do the hard work for you, producing a report on how likely your home is to be approved for an extension, along with approval stats in your area, the planning risks you may face, cost estimates, and the value an extension could add to your home.

The tool will even produce images of how each type of extension could look, giving you all the inspiration and practical considerations you need to get started on planning your dream home.

There's also the option to upgrade to a premium version, which provides an advanced analysis of your home, taking factors such as boundary lines, roof height, protected trees, and more into consideration for ultra-accurate results.

The premium version costs just £29 and lets you find out the exact dimensions likely to win planning approval, along with site-specific characteristics that might cause a refusal – giving you everything you need to prepare.

Extension on house with green details

Extension Potential tells you how likely you are to be approved for an extension (Image credit: Juliet Murphy)

How can the Extension Potential tool help me?

"Getting as much early information as possible about your extension options is a really important step in your home improvement journey,” says Beth Murton, editor of Homebuilding & Renovating. “Early research allows you to explore the different types of extension that might be possible for your home – such as rear, side return, wraparound or loft – and compare how each could work for your space.

"By gathering information like this upfront, along with expert advice on how likely planning permission will be approved, you can move from initial guesswork to informed decision-making.

"That’s why we’re really excited to be partnering with Resi on the new Extension Potential tool as we hope it will help give homeowners valuable inspiration and more clarity at the initial stages of their project. By using the tool they can quickly get an idea on where and how an extension will add the most value, functionality and long-term enjoyment to their home. It takes less than a minute to fill out the form and you'll get tailored results on your home's extension potential."

Beth Murton standing in front of open shelving and holding a pink coffee mug
Beth Murton

For the past 20+ years, Beth has worked for and contributed to a number of leading magazines and websites in the UK, including Homes & Gardens, Real Homes, Ideal Home, Period Living and Grand Designs.


If you're among the 42% of homeowners who feel their home doesn't fit their needs (according to Nic Yeeles), the Extension Potential tool is a great way to see whether an extension could work for you as a solution.

For a little inspiration on your journey, browse our favourite house extension ideas and kitchen extension ideas.

Megan Milstead
Content Editor

As Content Editor at Homebuilding & Renovating, Megan is passionate about providing expert-backed advice and creative inspiration to help readers transform their living spaces. Her love for DIY began while helping to renovate her parents’ family home, sparking a fascination with interiors, renovation, and design. More recently, she assisted with the renovation of her partner’s house in Bristol and is currently expanding her expertise through an Introduction to Home Improvement course. She joined the Homebuilding & Renovating team in 2025, having previously worked as a Staff Writer at PetsRadar and Beauty Assistant at Harrods.